1. Field of the Invention
The present invention relates to a folding device that cuts a continuous paper into sheets and folds the sheets formed by cutting the continuous paper, more specifically, to a folding device comprising a cutting mechanism and a folding cylinder and capable of collect folding that overlaps the sheets on a circumferential surface of the folding cylinder and folds the overlapped sheets.
2. Description of the Related Art
Disclosed in, for example, Patent Documents 1 and 2 identified below is a folding device capable of “collect folding”, comprising a cutting mechanism and a folding cylinder that are driven to rotate. The folding device cuts a continuous paper into sheets by a cutting blade provided in the cutting mechanism, holds the cut sheets at a circumferential surface of the folding cylinder by a sheet holding means provided in the folding cylinder, then, after rotating by an amount of a certain angle, thrusts out a middle portion of the held sheets from the circumferential surface of the folding cylinder toward between a folding roller pair located at positions facing one another or a jaw mechanism of a jaw cylinder by means of a folding blade provided in the folding cylinder, to fold these sheets at the middle portion. “Collect folding” refers to overlapping the sheets at the circumferential surface of the folding cylinder and then thrusting out the overlapped sheets by the folding blade to fold the sheets.
A folding device disclosed in Patent Document 1 comprises: a cutting cylinder including a cutting blade at two places in positions equally dividing an outer circumferential surface of the cutting cylinder in two; a folding cylinder which is provided such that its outer circumferential surface and the outer circumferential surface of the cutting cylinder are in close proximity with one another, has an outer circumferential dimension approximately 1.5 times that of the cutting cylinder, includes a cutting blade receiver at three places equally dividing the outer circumferential surface of the folding cylinder in three and capable of receiving a blade edge of the cutting blade, includes a paper holding pin projectable and retractable from the outer circumferential surface of the folding cylinder in close proximity to each of the cutting blade receivers, and, moreover, includes a folding blade projectable and retractable from the outer circumferential surface of the folding cylinder at three places approximately equally positioned between pin projecting/retracting positions in a circumferential direction of the outer circumferential surface; and a jaw cylinder which is provided such that its outer circumferential surface and the outer circumferential surface of the folding cylinder are in close proximity with one another, has an outer circumferential dimension approximately equal to that of the cutting cylinder, and includes a jaw mechanism at two places in positions equally dividing the outer circumferential surface of the jaw cylinder in two. In addition, a holding pin drive cam and a folding blade drive cam each provided with a concave portion displaced by 180 degrees on its circular outer circumferential surface are each provided at a position facing a side surface of the folding cylinder to be rotatable around an axial center of the folding cylinder with a rotational speed 1.5 times that of the folding cylinder, and, furthermore, a pin drive mask cam corresponding to the holding pin drive cam and provided with a concave portion at one place on its circular outer circumferential surface having the same diameter as the holding pin drive cam and a blade drive mask cam corresponding to the folding blade drive cam and provided with a concave portion at one place on its circular outer circumferential surface having the same diameter as the folding blade drive cam are each provided to be rotatable around the axial center of the folding cylinder with a rotational speed 1.5 times that of the folding cylinder, with the concave portion of the pin drive mask cam having a rotational phase identical to that of one of the concave portions of the holding pin drive cam in the case of the pin drive mask cam and with the concave portion of the blade drive mask cam having a rotational phase identical to that of one of the concave portions of the folding blade drive cam in the case of the blade drive mask cam, and are each provided such that moving in parallel to an axis direction of the folding cylinder enables displacement between a position preventing action of one of the concave portions of the corresponding drive cam and a position not preventing action of both of the concave portions of the corresponding drive cam. Moreover, the paper holding pin and the folding blade are each linked respectively to a pin support shaft or a blade support shaft parallel to a shaft of the folding cylinder, each of the support shafts has its end protruding from the side surface of the folding cylinder, and two cam followers are provided via arms to ends of each of the support shafts protruding from the side surface of the folding cylinder, one of the cam followers being provided to displace along the outer circumferential surface of the holding pin drive cam or the outer circumferential surface of the folding blade drive cam together with rotation of the folding cylinder, and the other of the cam followers being provided to displace along the outer circumferential surface of the pin drive mask cam or the outer circumferential surface of the blade drive mask cam that have displaced to the position disabling action of one of the concave portions of the drive cams together with rotation of the folding cylinder, and the two cam followers are provided such that, when one of the cam followers displaces following the concave portion of the drive cam, the support shaft undergoes angular displacement, the paper holding pin withdraws from the outer circumferential surface of the folding cylinder and the folding blade protrudes from the outer circumferential surface of the folding cylinder, and are provided such that withdrawal of the holding pin drive cam from the outer circumferential surface of the folding cylinder of the paper holding pin and protrusion of the folding blade drive cam from the outer circumferential surface of the folding cylinder of the folding blade are performed in an integrated manner.
Activating this folding device in a state where the pin drive mask cam and the blade drive mask cam have been displaced respectively to the position preventing action of one of the concave portions of the corresponding drive cam enables this folding device to perform “collect folding” which overlaps two sheets at the circumferential surface of the folding cylinder and then thrusts out the overlapped sheets by means of the folding blade to fold the sheets; activating this folding device in a state where the pin drive mask cam and the blade drive mask cam have been displaced respectively to the position not preventing action of both of the concave portions of the corresponding drive cams enables this folding device to perform “straight folding” which thrusts out the sheets by means of the folding blade without overlapping the sheets to fold the sheets.
A folding device disclosed in Patent Document 2 comprises: a cutting cylinder including a cutting blade at two places in positions equally dividing an outer circumferential surface of the cutting cylinder in two; a folding cylinder which is provided such that its outer circumferential surface and the outer circumferential surface of the cutting cylinder are in close proximity with one another, has an outer circumferential dimension approximately 1.5 times that of the cutting cylinder, includes a cutting blade receiver at three places equally dividing the outer circumferential surface of the folding cylinder in three and capable of receiving a blade edge of the cutting blade, includes a paper holding pin projectable and retractable from the outer circumferential surface of the folding cylinder in close proximity to each of the cutting blade receivers, and, moreover, includes a folding blade projectable and retractable from the outer circumferential surface of the folding cylinder at three places approximately equally positioned between pin projecting/retracting positions in a circumferential direction of the outer circumferential surface; and a jaw cylinder which is provided such that its outer circumferential surface and the outer circumferential surface of the folding cylinder are in close proximity with one another, has an outer circumferential dimension approximately equal to that of the cutting cylinder, and includes a jaw mechanism at two places in positions equally dividing the outer circumferential surface of the jaw cylinder in two. Alternatively, the folding device comprises a folding roller pair in place of the jaw mechanism, the folding roller pair provided in close proximity to the outer circumferential surface of the folding cylinder. In addition, a holding pin drive cam and a folding blade drive cam each provided with a concave portion on its circular outer circumferential surface are each provided fixed to a frame rotatably supporting the folding cylinder, at intervals in an axis direction of the folding cylinder, at a position facing a side surface of the folding cylinder, and, furthermore, a masking cam driven to rotate around an axial center of the folding cylinder is provided between the holding pin drive cam and the folding blade drive cam. The masking cam includes two half cams provided in a symmetrical positional relationship to an axial center of the masking cam, and these two half cams are configured to be movable in a radial direction of the masking cam. Further, when the half cam moves to a position of increased radius, the outer circumferential surface of the half cam attains an identical diameter to the outer circumferential surface of the holding pin drive cam and the folding blade drive cam, thereby preventing action of the concave portion provided to the holding pin drive cam and the folding blade drive cam. Moreover, when the half cam moves to a position of reduced radius, the outer circumferential surface of the half cam attains a position closer to the axial center of the masking cam than a bottom of the concave portion provided to the outer circumferential surface of the holding pin drive cam and the folding blade drive cam, thereby not preventing action of the concave portion provided to the holding pin drive cam and the folding blade drive cam. Note that when the folding cylinder has a configuration in which the paper holding pin and the folding blade are each provided in three places as previously described, a drive rotational speed of the masking cam is 0.75 times the rotational speed of the folding cylinder. Moreover, the paper holding pin and the folding blade are each linked respectively to a pin support shaft or a blade support shaft parallel to a shaft of the folding cylinder, each of the support shafts has its end protruding from the side surface of the folding cylinder, and two cam followers are provided via arms to ends of each of the support shafts protruding from the side surface of the folding cylinder, one of the cam followers being provided to displace along the outer circumferential surface of the holding pin drive cam or the outer circumferential surface of the folding blade drive cam together with rotation of the folding cylinder, and the other of the cam followers being provided to displace along the outer circumferential surface of the pin drive mask cam or the outer circumferential surface of the blade drive mask cam that have displaced to the position disabling action of one of the concave portions of the drive cams together with rotation of the folding cylinder, and the two cam followers are provided such that, when one of the cam followers displaces following the concave portion of the drive cam, the support shaft undergoes angular displacement, the paper holding pin withdraws from the outer circumferential surface of the folding cylinder and the folding blade protrudes from the outer circumferential surface of the folding cylinder, and are provided such that withdrawal of the holding pin drive cam from the outer circumferential surface of the folding cylinder of the paper holding pin and protrusion of the folding blade drive cam from the outer circumferential surface of the folding cylinder of the folding blade are performed in an integrated manner.
Activating this folding device in a state where either of the half cams of the masking cam has been moved to the position of increased radius and displaced to the position preventing action of the concave portion of the corresponding drive cam enables this folding device to perform “collect folding” which overlaps two sheets at the circumferential surface of the folding cylinder and then thrusts out the overlapped sheets by means of the folding blade to fold the sheets; activating this folding device in a state where either of the half cams of the masking cam has been moved to the position of increased radius and displaced to the position not preventing action of both of the concave portions of the corresponding drive earns enables this folding device to perform “straight folding” which thrusts out the sheets by means of the folding blade without overlapping the sheets to fold the sheets.
[Patent Document 1] JP 2000-505768 W
[Patent Document 2] JP 2008-56493 A